Successful data storage and transmission may be impeded by multi-bit or single bit errors present in the data. Hardware diagnostic tests use error correction codes (ECCs) to detect and correct single-bit errors, which are categorized as correctable errors. ECCs are also used to detect multi-bit errors, which are known as uncorrectable errors.
Detection of an uncorrectable error often prompts a machine check condition. If the computer system is alternatively running in memory mirrored mode, a hot memory replace may alternatively result. For example, if a read to a memory structure results in an uncorrectable error, the read is reissued to a complement memory structure. The complement memory structure functions as a mirror copy. The read data from the complement structure is returned to a requesting agent. The uncorrectable error is reported as a recoverable error. Subsequent reads are directed to a complement port while a hot memory replace is performed.
Use of a memory structure is limited while a machine check condition or a hot memory replace is accomplished. Therefore, limiting repair actions would be beneficial.